Conventionally, various studies have been conducted on techniques using Forward Error Correction (FEC) in an optical communication network. FEC is a technique for an optical transmitter and receiver on a reception side to recover from an error occurring in the course of data transfer.
Here, the optical transmitter and receiver consumes power when using FEC. Also, there are a plurality of FEC techniques. For example, the optical transmitter and receiver consumes more power when using a FEC technique with a high error-recovery performance than that when using a FEC technique with a low error-recovery performance.
Furthermore, in a conventional optical transmitter and receiver, a technique is used in which settings for FEC (FEC technique) are input by maintenance staff at the time of the initial start of the optical transmitter and receiver. Still further, for example, in a conventional optical transmitter and receiver, a technique is used in which maintenance staff manually switches the FEC technique. Still further, for example, a technique is used in which a transmission path for use in transmitting data is switched by an optical transmitter and receiver when the transmission quality is poor (for example, refer to Japanese Laid-open Patent Publication No. 2003-18096, pp. 5-7, FIG. 1).
Meanwhile, in the conventional technology, there is a problem of being incapable of reducing power consumption.
For example, in the conventional techniques, once the FEC technique is set by maintenance staff, the optical transmitter and receiver often operates with the FEC technique being unchanged thereafter. Therefore, in the conventional techniques, since the optical transmitter and receiver continues to use an FEC technique that may be inappropriate in view of power consumption, and thus cannot reduce power consumption.
Specifically, for example, in the conventional optical transmitter and receiver, depending on the setting by the customer, FEC always operates even when the use of FEC is not required. For example, FEC operates when an optical input to the receiving device breaks, when an error rate incapable of error correction is input to the receiving device, or when the transmission quality is good enough to dispense with error correction. With this, the conventional optical transmitter and receiver always wastes power by consuming power for operating FEC, for example. Note that the technique of switching the transmission path is not in consideration of reducing power consumption.